Export of Segment Routing over IPv6 Information in IP Flow Information Export (IPFIX)
draft-ietf-opsawg-ipfix-srv6-srh-14

[Ballot discuss]
Hi There,

Thanks for the document.

I am issuing a discuss based on section 6.3 of the document that I'd like to talk about.  RFC8200 Section 4.1 states:

Each extension header should occur at most once, except for the
  Destination Options header, which should occur at most twice (once
  before a Routing header and once before the upper-layer header).

I also note that RFC8200 is not written using normative language - but considering the context I am assuming that this should be read as such.

This directly conflicts with section 6.3 - which makes allowance for multiple SRH in the packet.  The only way that multiple SRH's should be allowed to occur in the packet is if the packet is re-encapsulated - at which point section 6.3 would still (in my view) not be referring to multiple SRH's - since the second SRH would be attached to a fully encapsulated packet.

If there is indeed a need for multiple SRH in IPFIX - this would require a pretty clear explanation as to why, how this could occur and a strong justification for violating RFC8200 in my opinion.

[Ballot comment]
# GEN AD review of draft-ietf-opsawg-ipfix-srv6-srh-11

CC @larseggert

## Nits

All comments below are about very minor potential issues that you may choose to
address in some way - or ignore - as you see fit. Some were flagged by
automated tools (via https://github.com/larseggert/ietf-reviewtool), so there
will likely be some false positives. There is no need to let me know what you
did with these suggestions.

### Grammar/style

#### Section 3, paragraph 10
```
s information [IANA-IPFIX] allow to provide answers to the following questio
                                ^^^^^^^^^^
```
Did you mean "providing"? Or maybe you should add a pronoun? In active voice,
"allow" + "to" takes an object, usually a pronoun.

#### Section 5.1.10, paragraph 5
```
as a list, without the need of post processing. However, this method require
                              ^^^^^^^^^^^^^^^
```
This word is normally spelled with a hyphen.

#### Section 6.1, paragraph 6
```
emented the following IEs as part of a a production implementation in the VRP
                                    ^^^
```
Possible typo: you repeated a word.

#### Section 6.2, paragraph 1
```
ListSection decomposition as part of a a production implementation in the ope
                                    ^^^
```
Possible typo: you repeated a word.

## Notes

This review is in the ["IETF Comments" Markdown format][ICMF], You can use the
[`ietf-comments` tool][ICT] to automatically convert this review into
individual GitHub issues. Review generated by the [`ietf-reviewtool`][IRT].

[ICMF]: https://github.com/mnot/ietf-comments/blob/main/format.md
[ICT]: https://github.com/mnot/ietf-comments
[IRT]: https://github.com/larseggert/ietf-reviewtool

[Ballot comment]
Thanks for your work to address my previous DISCUSS and COMMENT. There is a residual comment, which is the question of how srhIPv6Section should be formed if there is no SRH in the packet. In his reply, Thomas said,

> In case when the compressed SID container is only used in the IPv6 destination address of the provider data plane and the SRH is not being present at all, it would be a zero lenght array.

Perhaps adding some text to that effect might be worthwhile.

[Ballot comment]
# Internet AD comments for draft-ietf-opsawg-ipfix-srv6-srh-12
CC @ekline

* comment syntax:
  - https://github.com/mnot/ietf-comments/blob/main/format.md

* "Handling Ballot Positions":
  - https://ietf.org/about/groups/iesg/statements/handling-ballot-positions/

## Comments

### S6.2

* We might clarify here that no export method involves any "decompression"
  of a compressed SID.  (I assume unpacking a compressed SID is entirely the
  responsibility of an analysis function within or downstream of the
  collector.)

## Nits

### S5.2

* s/designed experts/designated experts/

[Ballot discuss]
Thanks to Mohamed Boucadair for the high-quality shepherd write-up with illuminating details.

I have one point I'd like to have a discussion about. As you note in Section 6.2, compressed segment lists are a thing, and one of their implications is that (with certain flavors) one can have an SRH-less SRv6 packet, a "bare cSID". I wonder if it would be desirable to elaborate on how (for example) the srhSegmentIPv6ListSection is to be formed (I guess it might just be a verbatim copy of the cSID, and the importer has to do the work to figure it out?) or how the srhSegmentIPv6BasicList is to be formed (I guess the exporter has to do the work to decompress the cSID to provide the expanded representation). And what of srhIPv6Section? Would it just be omitted in the case of a bare cSID, would it be a zero-length octetArray, ...?

I don't have a fixed idea of how (or even if) the document should be changed to address this question but I'd like to know the authors' thoughts on the matter.

[Ballot discuss]
Thanks to Mohamed Boucadair for the high-quality shepherd write-up with illuminating details.

I have one point I'd like to have a discussion about. As you point out in Section 6.2, compressed segment lists are a thing, and one of their implications is that (with certain flavors) one can have an SRH-less SRv6 packet, a "bare cSID". I wonder if it would be desirable to elaborate on how (for example) the srhSegmentIPv6ListSection is to be formed (I guess it might just be a verbatim copy of the cSID, and the importer has to do the work to figure it out?) or how the srhSegmentIPv6BasicList is to be formed (I guess the exporter has to do the work to decompress the cSID to provide the expanded representation). And what of srhIPv6Section? Would it just be omitted in the case of a bare cSID, would it be a zero-length octetArray, ...?

I don't have a fixed idea of how (or even if) the document should be changed to address this question but I'd like to know the authors' thoughts on the matter.

[Ballot comment]
srhIPv6ActiveSegmentType is described (in a couple places) as the "name of the routing protocol". It's not a name, though, that would imply a string. It's a designator; the protocol is named in the associated IANA registry, not the information element itself. Probably you could fix this by just dropping "name of the" although you could also change it to something like "designator of the".

[Ballot comment]
Thank you to Tero Kivinen for the SECDIR review.

** Section 9
  There exists no significant extra security considerations regarding
  allocation of these new IPFIX IEs compared to [RFC7012]

What are the “non-significant extra security considerations” not mentioned in RFC7012?  The text implies there is something more to say.

** Section 9.
  Privacy considerations described in Section 11.8 of [RFC7012] SHOULD
  be considered for all described IEs.  They export provider data plane
  metrics which describe how packets are being forwarded within the
  SRv6 network.


-- Typo.  This text should reference Section 11.8 of RFC7011.  RFC7012 has no privacy consideration and no Section 11.

-- Even though this is a data model, the clarity of “SHOULD ... consider” language (here) to text which has non-normative “mays” and “musts” (of RFC7011) is murky.  Consider if it is more appropriate to say “must”.  For example:

NEW
The IEs described in this document export provider plane data metrics on how packets are being forwarded within an SRv6 network. Applications and operators using the IEs described in this document must evaluate the sensitivity of this information in their implementation context, and apply the data-at-rest storage guidance in Section 11.8 of RFC7011 as appropriate.

[Ballot comment]
# Éric Vyncke, INT AD, comments for draft-ietf-opsawg-ipfix-srv6-srh-10

Thank you for the work put into this document.

Please find below some non-blocking COMMENT points (but replies would be appreciated even if only for my own education).

Special thanks to Mohamed Boucadair for the shepherd's detailed write-up including the WG consensus and the justification of the intended status.

I hope that this review helps to improve the document,

Regards,

-éric

## COMMENTS

### More than data plane

I like the idea of exporting srhIPv6ActiveSegmentType for operation, it goes well beyond the plain export of the SRH header. I just fear that the extra information is redundant and will be repeated quite often.

### Section 5.1.9

What would happen if this information is learned by two sources ?

### Section 6.3

Beside encapsulation, I do not see how multiple (S)RHs could be in one IPv6 packet. Anyway, the router will, per RFC 8200, only act on the outermost one. I.e., strongly suggest that this I-D specifies that only the outermost SRH & associated behavior are specified.

[Ballot comment]
# Éric Vyncke, INT AD, comments for draft-ietf-opsawg-ipfix-srv6-srh-10

Thank you for the work put into this document.

Please find below some non-blocking COMMENT points (but replies would be appreciated even if only for my own education).

Special thanks to Mohamed Boucadair for the shepherd's detailed write-up including the WG consensus and the justification of the intended status.

I hope that this review helps to improve the document,

Regards,

-éric

## COMMENTS

### More than data plane

I like the idea of exporting srhIPv6ActiveSegmentType for operation, it goes well beyond the plain export of the SRH header. I just fear that the extrinformation is redundant and will be repeated quite often.

### Section 5.1.9

What would happen if this information is learned by two sources ?

### Section 6.3

Beside encapsulation, I do not see how multiple (S)RH could be in one IPv6 packet. Anyway, the router will, per RFC 8200, only act on the outermost one. I.e., strongly suggest that this I-D specifies that only the outermost SRH & associated behavior are specified.

[Ballot discuss]
Section 1:

  Also, three routing protocol extensions, OSPFv3 [RFC9352], IS-IS
  [I-D.ietf-lsr-isis-srv6-extensions] and BGP Prefix Segment
  Identifiers(Prefix-SIDs) [RFC9252]

The above needs to be fixed. OSPFv3 is not [RFC9352] and I assume that the reference should point to https://datatracker.ietf.org/doc/draft-ietf-lsr-ospfv3-srv6-extensions/, ietf-lsr-isis-srv6-extensions is an out-of-date reference as it is now https://www.rfc-editor.org/rfc/rfc9352, and RFC 9252 is "BGP Overlay Services Based on Segment Routing over IPv6 (SRv6)" that provides protocol extensions for SRv6-based BGP services.

Section 3:

  srhSegmentsIPv6Left
      8-bit unsigned integer defining the number of segments remaining
      to reach the end of the segment list as defined in Section 2 of
      [RFC8754].

The above description is not technically accurate. While section 2 of RFC8754 does define the SRH, the 'Segments Left' field of the SRH is actually defined in Section 4.4 of RFC8200 (https://www.rfc-editor.org/rfc/rfc8200#section-4.4) and RFC8754 points to that reference. Section 5.7 of this document should also point to the correct reference.

Section 5.9.1:

  | TBD15 | OSPFv3            | [RFC-to-be],  |
  |      | Segment Routing    |                                      |
  +-------+--------------------+---------------------------------------+
  | TBD16 | IS-IS              | [RFC-to-be],  |
  +-------+--------------------+---------------------------------------+
These references need to be corrected as indicated above.

[Ballot comment]
Section 6.2:

  The SID endpoint behaviors described in section 4 of
  [I-D.ietf-spring-srv6-srh-compression] determine wherever the segment
  list is compressed or not.

Section 4 of the referenced draft does not define new endpoint behaviors for SRv6; the document defines new flavors for existing behaviors.

# Document Shepherd Write-Up for draft-ietf-opsawg-ipfix-srv6-srh-08

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

There is a broad agreement to adopt and progress this work within OPSAWG. Also,
this work benefited from cross-wg checks (see below). There was also a fair
support from implementers (see below).

The proposal has been demonstrated at the IETF#115 Hackathon. No issue was
reported.


2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

No controversy is to be reported for the draft. The authors were responsive in
dealing with the comments raised by reviewers. One aspect that required some cycles
is related to the IANA actions. For example, previous versions of the specification
requested the creation of new registries that are redundant with existing IANA
registries. That design was problematic. That issue and similar ones were fixed in
subsequent iterations of the draft after consulting with the IANA.

The following main comments were raised by the DEs during the IETF Last Call:

* Whether "IPv6" has to appear in the IE names: It is true that SRH is for IPv6, and one
  would claim that having IPv6 included is redundant. However, including IPv6
  in the the IE names as this is an explicit indication about the applicability of an IE.
  FWIW, other registries insist on the V6 thing even for IPv6-only registries (see for
  example all the options starting with “OPTION_V6” in https://www.iana.org/assignments/dhcpv6-parameters/dhcpv6-parameters.xhtml). 

* Inconsistent naming when IPv6 is included in the name (e.g., as to whether "IPv6" is in
the middle, at the end, ..): FWIW, there are no rules out there as there are IPFIX IEs
such as sourceIPv6Address, destinationIPv6PrefixLength, flowLabelIPv6,
ipv6ExtensionHeaders, icmpCodeIPv6, etc. However, the authors made changes to some IEs
to ensure "some" consistency: e.g., s/srhSectionIPv6/srhIPv6Section.

* srhSegmentIPv6BasicListseems to be a raw dump of srhSegmentIPv6BasicList. The same comment
  was also raised for srhIPv6Section. The authors explained that although they prefer
  srhSegmentIPv6BasicList, there is lack of RFC6313 implementations, hence these two IEs.

  The following note is in the draft

    "It is not expected that an exporter would support both
    srhSegmentIPv6BasicList and srhSegmentIPv6ListSection at the same time."
 
  Andrew Feren (DE) agreed with the authors, while Paul Aitken (DE) maintained his objections.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

Yes. At least, the following implementations were disclosed:

* open-source flow collector pmacct: [https://github.com/pmacct/pmacct]
* VPP: [https://github.com/insa-unyte/vpp-srh-onpath-telemetry]
* Huawei VRP

More information about these implementations are available at:
[draft-ietf-opsawg-ipfix-srv6-srh-06.html#name-implementation-status].


## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.


Yes:

* Early versions of this specification were presented at OPSAWG and SPRING
  (IETF#113) and 6man (IETF#114).
* The authors systematically sent notifications to SPRING/6MAN WGs when new
  revisions were released (e.g., [https://mailarchive.ietf.org/arch/msg/spring/E7E8SEKuP2gjklFxljZR6WwwvLU/]),
  including when a call for adoption was initiated in OPSAWG and then past adoptions.
* The WGLC was also circulated in SPRING ([https://mailarchive.ietf.org/arch/msg/spring/vCslo9FALtLsuTTFr3ZhZStUqv8/])
  and 6man ([https://mailarchive.ietf.org/arch/msg/ipv6/iHvRL9SwSY-gMEpLuM0uhZdnytM/]).
  No follow-up was received in these lists, though.


6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

No formal review is required other than the review required to perform the IANA
actions (i.e., new IPFIX IE assignments).

Early IANA allocation as per [https://datatracker.ietf.org/doc/html/rfc7120#section-2]
considered by the authors.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.


8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.


10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

The document was already socialized in 6man and spring.


11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

This document requests publication as a Proposed Standard RFC. That
is indicated on the header page. The intended status is justified
given that the document specifies new IPFIX IEs with a set of normative
behavior to ensure interoperability.


12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes. An IPR poll was issued by Joe. All authors replied to that poll:


* Thomas Graf: https://mailarchive.ietf.org/arch/msg/opsawg/QLID8Pvu_neDIRA-RUwosf5ynbQ/
* Benoit Claise: https://mailarchive.ietf.org/arch/msg/opsawg/EmjEkESHERsW8WN32cVI0MyUiwQ/
* Pierre François: https://mailarchive.ietf.org/arch/msg/opsawg/7wQJw5X9s5m1_LvqJTdNbR4QdH8/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

I guess so. At least, none of the listed authors complained.


14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

None to report for -06.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

None.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

N/A.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

No.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

No.


20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

See, e.g., https://github.com/boucadair/IETF-Drafts-Reviews/raw/master/draft-tgraf-opsawg-ipfix-srv6-srh-05-rev%20Med.pdf

The Shepherd review of the document triggered discussions with IANA and updated to
the IANA considerations section to implement the proposed changes (see
[https://mailarchive.ietf.org/arch/msg/opsawg/_NruNADG4FWAE5H4ErM0zIEVwCs/]).

All requested actions are clearly documented, with adequate pointers to the target
IANA registry.

The document requests the creation of a new sub-registry (IPFIX IPv6 SRH Segment
Type). The initial content is provided.


21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

The new sub-registry "IPFIX IPv6 SRH Segment Type Subregistry".

Some instructions are provided to the Designated Experts. Even if this is
too brief, this is aligned with IPFIX practices.


[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://trac.ietf.org/trac/ops/wiki/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://trac.ietf.org/trac/iesg/wiki/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

The IANA Functions Operator has completed its review of draft-ietf-opsawg-ipfix-srv6-srh-08. If any part of this review is inaccurate, please let us know.

The IANA Functions Operator understands that, upon approval of this document, there are two actions which we must complete.

First, in the IPFIX Information Elements registry on the IP Flow Information Export (IPFIX) Entities registry page located at:

https://www.iana.org/assignments/ipfix/

eleven new registrations are to be made as follows:

Name: srhFlagsIPv6
ElementID: [ TBD-at-Registration ]
Description: The 8-bit flags defined in the SRH. Assigned flags and their meanings are provided in the "Segment Routing Header Flags" IANA registry.
Abstract Data Type: unsigned8
Data Type Semantics: flags
Additional Information: RFC8754. See the assignments in the "Segment Routing Header Flags" IANA registry at https://www.iana.org/assignments/ipv6- parameters/ipv6-parameters.xhtml#segment-routing-header-flags
Reference: [RFC-to-be]

Name: srhTagIPv6
ElementID: [ TBD-at-Registration ]
Description: The 16-bit tag field defined in the SRH that marks a packet as part of a class or group of packets sharing the same set of properties.
Abstract Data Type: unsigned16
Data Type Semantics: identifier
Additional Information: RFC8754
Reference: [RFC-to-be]

Name: srhSegmentIPv6
ElementID: [ TBD-at-Registration ]
Description: The 128-bit IPv6 address that represents an SRv6 segment.
Abstract Data Type: ipv6address
Data Type Semantics: default
Additional Information: RFC8754
Reference: [RFC-to-be]

Name: srhActiveSegmentIPv6
ElementID: [ TBD-at-Registration ]
Description: The 128-bit IPv6 address that represents the active SRv6 segment.
Abstract Data Type: ipv6address
Data Type Semantics: default
Additional Information: RFC8754
Reference: [RFC-to-be]

Name: srhSegmentIPv6BasicList
ElementID: [ TBD-at-Registration ]
Description: The Ordered basicList [RFC6313] of zero or more 128-bit IPv6 addresses in the SRH that represents the SRv6 segment list. As described in section 2 of [RFC8754], the Segment List is encoded starting from the last segment of the SR Policy. That is, the first element of the Segment List (Segment List[0]) contains the last segment of the SR Policy, the second element contains the penultimate segment of the SR Policy, and so on.
Abstract Data Type: basicList
Data Type Semantics: list
Additional Information: RFC8754
Reference: [RFC-to-be]

Name: srhSegmentIPv6ListSection
ElementID: [ TBD-at-Registration ]
Description: The SRH Segment List as defined in section 2 and section 2.1 of [RFC8754] as series of octets.
Abstract Data Type: octetArray
Data Type Semantics: default
Additional Information: RFC8754
Reference: [RFC-to-be]

Name: srhSegmentsIPv6Left
ElementID: [ TBD-at-Registration ]
Description: The 8-bit unsigned integer defining the number of route segments remaining to reach the end of the segment list as defined in Section 2 of [RFC8754].
Abstract Data Type: unsigned8
Data Type Semantics: quantity
Additional Information: RFC8754
Reference: [RFC-to-be]

Name: srhIPv6Section
ElementID: [ TBD-at-Registration ]
Description: The SRH and its TLVs as defined in Section 2 of [RFC8754] as series of octets.
Abstract Data Type: octetArray
Data Type Semantics: default
Additional Information: RFC8754
Reference: [RFC-to-be]



IANA NOTE --> The following registration depends upon the second action (below) being completed. IANA will replace the text "[IPFIX IPv6 SRH Segment Type Subregistry]" with the appropriate URL.



Name: srhIPv6ActiveSegmentType
ElementID: [ TBD-at-Registration ]
Description: The name of the routing protocol or PCEP extension from where the active SRv6 segment has been learned from. Values for this Information Element are listed in the "IPFIX IPv6 SRH Segment type" subregistry, see [IPFIX IPv6 SRH Segment Type Subregistry].
Abstract Data Type: unsigned8
Data Type Semantics: identifier
Additional Information: [IPFIX IPv6 SRH Segment Type Subregistry]
Reference: [RFC-to-be]

Name: srhSegmentIPv6LocatorLength
ElementID: [ TBD-at-Registration ]
Description: The SRH segment IPv6 locator length specified as the number of significant bits. Together with srhSegmentIPv6 it enables the calculation of the SRv6 Locator
Abstract Data Type: unsigned8
Data Type Semantics: default
Additional Information: Section 3.1 of RFC8986
Reference: [RFC-to-be]

Name: srhSegmentIPv6EndpointBehavior
ElementID: [ TBD-at-Registration ]
Description: The 16-bit SRv6 Endpoint behavior. Assigned values and their meanings are provided in the "SRV6 Endpoint Behavior" registry.
Abstract Data Type: unsigned16
Data Type Semantics: identifier
Additional Information: See the "SRV6 Endpoint Behavior" registry at https://www.iana.org/assignments/segment-routing/ Section 4 of RFC8986.
Reference: [RFC-to-be]

As this document requests registrations in an Expert Review or Specification Required (see RFC 8126) registry, we will initiate the required Expert Review via a separate request. This review must be completed before the document's IANA state can be changed to "IANA OK."

Second, a new registry will be created called the IPFIX IPv6 SRH Segment Type Subregistry. The new registry will be located on the IP Flow Information Export (IPFIX) Entities registry page located at:

https://www.iana.org/assignments/ipfix/

The registry will be maintained via Expert Review as defined in RFC8126. There are six initial registrations in the new registry as follows:

+-------------------------+--------------------+---------------------------------------+---------------+
| Value | Description | Additional Information | Reference |
+-------------------------+--------------------+---------------------------------------+---------------+
| [ TBD-at-Registration ] | Unknown | [RFC-to-be] | [ RFC-to-be ] |
| | | | |
+-------------------------+--------------------+---------------------------------------+---------------+
| [ TBD-at-Registration ] | Segment Routing | [RFC-to-be], | [ RFC-to-be ] |
| | Policy |  | |
+-------------------------+--------------------+---------------------------------------+---------------+
| [ TBD-at-Registration ] | Path Computation | [RFC-to-be], | |
+-------------------------+--------------------+---------------------------------------+---------------+
| [ TBD-at-Registration ] | OSPFv3 | [RFC-to-be], | [ RFC-to-be ] |
| | Segment Routing | | |
+-------------------------+--------------------+---------------------------------------+---------------+
| [ TBD-at-Registration ] | IS-IS | [RFC-to-be], | |
+-------------------------+--------------------+---------------------------------------+---------------+
| [ TBD-at-Registration ] | BGP Segment | [RFC-to-be], | [ RFC-to-be ] |
| | Routing Prefix-SID |  | |
+-------------------------+--------------------+---------------------------------------+---------------+

The IANA Functions Operator understands that these are the only actions required to be completed upon approval of this document.

Note:  The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is meant only to confirm the list of actions that will be performed.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Specialist

The following Last Call announcement was sent out (ends 2023-05-04):

From: The IESG
To: IETF-Announce
CC: draft-ietf-opsawg-ipfix-srv6-srh@ietf.org, mohamed.boucadair@orange.com, opsawg-chairs@ietf.org, opsawg@ietf.org, rwilton@cisco.com
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (Export of Segment Routing over IPv6 Information in IP Flow Information Export (IPFIX)) to Proposed Standard


The IESG has received a request from the Operations and Management Area
Working Group WG (opsawg) to consider the following document: - 'Export of
Segment Routing over IPv6 Information in IP Flow Information
  Export (IPFIX)'
  as Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
last-call@ietf.org mailing lists by 2023-05-04. Exceptionally, comments may
be sent to iesg@ietf.org instead. In either case, please retain the beginning
of the Subject line to allow automated sorting.

Abstract


  This document introduces new IP Flow Information Export (IPFIX)
  Information Elements to identify a set of Segment Routing over IPv6
  (SRv6) related information such as data contained in a Segment
  Routing Header (SRH), the SRv6 control plane, and the SRv6 endpoint
  behavior that traffic is being forwarded with.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-opsawg-ipfix-srv6-srh/



No IPR declarations have been submitted directly on this I-D.

# Document Shepherd Write-Up for draft-ietf-opsawg-ipfix-srv6-srh-06

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

There is a broad agreement to adopt and progress this work within OPSAWG. Also,
this work benefited from cross-wg checks (see below). There was also a fair
support from implementers (see below).

The proposal has been demonstrated at the IETF#115 Hackathon. No issue was
reported.


2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

No controversy is to be reported for the draft. The authors were responsive in
dealing with the comments raised by reviewers. One aspect that required some cycles
is related to the IANA actions. For example, previous versions of the specification
requested the creation of new registries that are redundant with existing IANA
registries. That design was problematic. That issue and similar ones were fixed in
subsequent iterations of the draft after consulting with the IANA.


3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

Yes. At least, the following implementations were disclosed:

* open-source flow collector pmacct: [https://github.com/pmacct/pmacct]
* VPP: [https://github.com/insa-unyte/vpp-srh-onpath-telemetry]
* Huawei VRP

More information about these implementations are available at:
[draft-ietf-opsawg-ipfix-srv6-srh-06.html#name-implementation-status].


## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.


Yes:

* Early versions of this specification were presented at OPSAWG and SPRING
  (IETF#113) and 6man (IETF#114).
* The authors systematically sent notifications to SPRING/6MAN WGs when new
  revisions were released (e.g., [https://mailarchive.ietf.org/arch/msg/spring/E7E8SEKuP2gjklFxljZR6WwwvLU/]),
  including when a call for adoption was initiated in OPSAWG and then past adoptions.
* The WGLC was also circulated in SPRING ([https://mailarchive.ietf.org/arch/msg/spring/vCslo9FALtLsuTTFr3ZhZStUqv8/])
  and 6man ([https://mailarchive.ietf.org/arch/msg/ipv6/iHvRL9SwSY-gMEpLuM0uhZdnytM/]).
  No follow-up was received in these lists, though.


6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

No formal review is required other than the review required to perform the IANA
actions (i.e., new IPFIX IE assignments).

Early IANA allocation as per [https://datatracker.ietf.org/doc/html/rfc7120#section-2]
considered by the authors.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.


8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.


10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

The document was already socialized in 6man and spring.


11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

This document requests publication as a Proposed Standard RFC. That
is indicated on the header page. The intended status is justified
given that the document specifies new IPFIX IEs with a set of normative
behavior to ensure interoperability.


12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes. An IPR poll was issued by Joe. All authors replied to that poll:


* Thomas Graf: https://mailarchive.ietf.org/arch/msg/opsawg/QLID8Pvu_neDIRA-RUwosf5ynbQ/
* Benoit Claise: https://mailarchive.ietf.org/arch/msg/opsawg/EmjEkESHERsW8WN32cVI0MyUiwQ/
* Pierre François: https://mailarchive.ietf.org/arch/msg/opsawg/7wQJw5X9s5m1_LvqJTdNbR4QdH8/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

I guess so. At least, none of the listed authors complained.


14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

None to report for -06.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

None.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

N/A.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

No.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

No.


20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

See, e.g., https://github.com/boucadair/IETF-Drafts-Reviews/raw/master/draft-tgraf-opsawg-ipfix-srv6-srh-05-rev%20Med.pdf

The Shepherd review of the document triggered discussions with IANA and updated to
the IANA considerations section to implement the proposed changes (see
[https://mailarchive.ietf.org/arch/msg/opsawg/_NruNADG4FWAE5H4ErM0zIEVwCs/]).

All requested actions are clearly documented, with adequate pointers to the target
IANA registry.

The document requests the creation of a new sub-registry (IPFIX IPv6 SRH Segment
Type). The initial content is provided.


21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

The new sub-registry "IPFIX IPv6 SRH Segment Type Subregistry".

Some instructions are provided to the Designated Experts. Even if this is
too brief, this is aligned with IPFIX practices.


[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://trac.ietf.org/trac/ops/wiki/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://trac.ietf.org/trac/iesg/wiki/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

# Document Shepherd Write-Up for draft-ietf-opsawg-ipfix-srv6-srh-06

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

There is a broad agreement to adopt and progress this work within OPSAWG. Also,
this work benefited from cross-wg checks (see below). There was also a fair
support from implementers (see below).

The proposal has been demonstrated at the IETF#115 Hackathon. No issue was
reported.


2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

No controversy is to be reported for the draft. The authors were responsive in
dealing with the comments raised by reviewers. One aspect that required some cycles
is related to the IANA actions. For example, previous versions of the specification
requested the creation of new registries that are redundant with existing IANA
registries. That design was problematic. That issue and similar ones were fixed in
subsequent iterations of the draft after consulting with the IANA.


3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

Yes. At least, the following implementations were disclosed:

* open-source flow collector pmacct: [https://github.com/pmacct/pmacct]
* VPP: [https://github.com/insa-unyte/vpp-srh-onpath-telemetry]
* Huawei VRP

More information about these implementations are available at:
[draft-ietf-opsawg-ipfix-srv6-srh-06.html#name-implementation-status].


## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.


Yes:

* Early versions of this specification were presented at OPSAWG and SPRING
  (IETF#113) and 6man (IETF#114).
* The authors systematically sent notifications to SPRING/6MAN WGs when new
  revisions were released (e.g., [https://mailarchive.ietf.org/arch/msg/spring/E7E8SEKuP2gjklFxljZR6WwwvLU/]),
  including when a call for adoption was initiated in OPSAWG and then past adoptions.
* The WGLC was also circulated in SPRING ([https://mailarchive.ietf.org/arch/msg/spring/vCslo9FALtLsuTTFr3ZhZStUqv8/])
  and 6man ([https://mailarchive.ietf.org/arch/msg/ipv6/iHvRL9SwSY-gMEpLuM0uhZdnytM/]).
  No follow-up was received in these lists, though.


6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

No formal review is required other than the review required to perform the IANA
actions (i.e., new IPFIX IE assignments).

Early IANA allocation as per [https://datatracker.ietf.org/doc/html/rfc7120#section-2]
considered by the authors.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.


8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.


10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

The document was already socialized in 6man and spring.


11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

This document requests publication as a Proposed Standard RFC. That
is indicated on the header page. The intended status is justified
given that the document specifies new IPFIX IEs with a set of normative
behavior to ensure interoperability.


12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes. An IPR poll was issued by Joe. All authors replied to that poll:


* Thomas Graf: https://mailarchive.ietf.org/arch/msg/opsawg/QLID8Pvu_neDIRA-RUwosf5ynbQ/
* Benoit Claise: https://mailarchive.ietf.org/arch/msg/opsawg/EmjEkESHERsW8WN32cVI0MyUiwQ/
* Pierre François: https://mailarchive.ietf.org/arch/msg/opsawg/7wQJw5X9s5m1_LvqJTdNbR4QdH8/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

I guess so. At least, none of the listed authors complained.


14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

None to report for -06.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

None.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

N/A.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

No.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

No.


20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

See, e.g., https://github.com/boucadair/IETF-Drafts-Reviews/raw/master/draft-tgraf-opsawg-ipfix-srv6-srh-05-rev%20Med.pdf

The Shepherd review of the document triggered discussions with IANA and updated to
the IANA considerations section to implement the proposed changes (see
[https://mailarchive.ietf.org/arch/msg/opsawg/_NruNADG4FWAE5H4ErM0zIEVwCs/]).

All requested actions are clearly documented, with adequate pointers to the target
IANA registry.

The document requests the creation of a new sub-registry (IPFIX IPv6 SRH Segment
Type). The initial content is provided.


21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

The new sub-registry "IPFIX IPv6 SRH Segment Type Subregistry".

Some instructions are provided to the Designated Experts. Even if this is
too brief, this is aligned with IPFIX practices.


[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://trac.ietf.org/trac/ops/wiki/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://trac.ietf.org/trac/iesg/wiki/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

# Document Shepherd Write-Up for draft-ietf-opsawg-ipfix-srv6-srh-06

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

There is a broad agreement to adopt and progress this work within OPSAWG. Also,
this work benefited from cross-wg checks (see below). There was also a fair
support from implementers (see below).

The proposal has been demonstrated at the IETF#115 Hackathon. No issue was
reported.


2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

No controversy is to be reported for the draft. The authors were responsive in
dealing with the comments raised by reviewers. One aspect that required some cycles
is related to the IANA actions. For example, previous versions of the specification
requested the creation of new registries that are redundant with existing IANA
registries. That design was problematic. That issue and similar ones were fixed in
subsequent iterations of the draft after consulting with the IANA.


3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

Yes. At least, the following implementations were disclosed:

* open-source flow collector pmacct: [https://github.com/pmacct/pmacct]
* VPP: [https://github.com/insa-unyte/vpp-srh-onpath-telemetry]
* Huawei VRP

More information about these implementations are available at:
[draft-ietf-opsawg-ipfix-srv6-srh-06.html#name-implementation-status].


## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.


Yes:

* Early versions of this specification were presented at OPSAWG and SPRING
  (IETF#113) and 6man (IETF#114).
* The authors systematically sent notifications to SPRING/6MAN WGs when new
  revisions were released (e.g., [https://mailarchive.ietf.org/arch/msg/spring/E7E8SEKuP2gjklFxljZR6WwwvLU/]),
  including when a call for adoption was initiated in OPSAWG and then past adoptions.
* The WGLC was also circulated in SPRING ([https://mailarchive.ietf.org/arch/msg/spring/vCslo9FALtLsuTTFr3ZhZStUqv8/])
  and 6man ([https://mailarchive.ietf.org/arch/msg/ipv6/iHvRL9SwSY-gMEpLuM0uhZdnytM/]).
  No follow-up was received in these lists, though.


6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

No formal review is required other than the review required to perform the IANA
actions (i.e., new IPFIX IE assignments).

Early IANA allocation as per [https://datatracker.ietf.org/doc/html/rfc7120#section-2]
considered by the authors.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.


8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.


10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

The document was already socialized in 6man and spring.


11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

This document requests publication as a Proposed Standard RFC. That
is indicated on the header page. The intended status is justified
given that the document specifies new IPFIX IEs with a set of normative
behavior to ensure interoperability.


12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes. An IPR poll was issued by Joe. All authors replied to that poll:


* Thomas Graf: https://mailarchive.ietf.org/arch/msg/opsawg/QLID8Pvu_neDIRA-RUwosf5ynbQ/
* Benoit Claise: https://mailarchive.ietf.org/arch/msg/opsawg/EmjEkESHERsW8WN32cVI0MyUiwQ/
* Pierre François: https://mailarchive.ietf.org/arch/msg/opsawg/7wQJw5X9s5m1_LvqJTdNbR4QdH8/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

I guess so. At least, none of the listed authors complained.


14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

None to report for -06.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

None.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

N/A.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

No.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

No.


20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

See, e.g., https://github.com/boucadair/IETF-Drafts-Reviews/raw/master/draft-tgraf-opsawg-ipfix-srv6-srh-05-rev%20Med.pdf

The Shepherd review of the document triggered discussions with IANA and updated to
the IANA considerations section to implement the proposed changes (see
[https://mailarchive.ietf.org/arch/msg/opsawg/_NruNADG4FWAE5H4ErM0zIEVwCs/]).

All requested actions are clearly documented, with adequate pointers to the target
IANA registry.

The document requests the creation of a new sub-registry (IPFIX IPv6 SRH Segment
Type). The initial content is provided.


21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

The new sub-registry "IPFIX IPv6 SRH Segment Type Subregistry".

Some instructions ere provided to the Designated Experts. Even if this is
too brief, this is aligned with IPFIX practices.


[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://trac.ietf.org/trac/ops/wiki/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://trac.ietf.org/trac/iesg/wiki/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

# Document Shepherd Write-Up for Group Documents

== LOG ===

Waiting for a revision to address the pending issues:
* Section “5.9.  srhActiveSegmentIPv6Type”: please add the pointer to the IANA registry under “Additional Information”. Please see the proposal from Benoît at: https://mailarchive.ietf.org/arch/msg/opsawg/ZZ5anFVYpabnmm12sfkmGB6nHYI/

* The text about multiple SRH is somehow "misleading" as it can be interpreted  as 8200 discusses explicitly multiple SRHs case. Also, and unless I' mistaken, there is no spring document that motivates the need for multiple SRHs or how these can be used. I suggest to simplify the wording of 6.3 to basically say: if multiple SRHs are observed (for reasons that are not detailed here), exporting multiple IEs is allowed + follow the base reco in 7011 for the ordering. No normative language is needed for this behavior.

* Please define what is meant by "active SRH".

======
IPR Replies (OK)
* Thomas Graf: https://mailarchive.ietf.org/arch/msg/opsawg/QLID8Pvu_neDIRA-RUwosf5ynbQ/
* Benoit Claise: https://mailarchive.ietf.org/arch/msg/opsawg/EmjEkESHERsW8WN32cVI0MyUiwQ/
* Pierre Francois: https://mailarchive.ietf.org/arch/msg/opsawg/7wQJw5X9s5m1_LvqJTdNbR4QdH8/

Implementations:
* open-source flow collector pmacct: https://github.com/pmacct/pmacct
* VPP: https://github.com/insa-unyte/vpp-srh-onpath-telemetry

hackathons:
* The proposal has been demonstrated at the IETF 115 hackathon
====

Cross-WG Reviews: OK

* The WGLC was also circulated in SPRING (https://mailarchive.ietf.org/arch/msg/spring/vCslo9FALtLsuTTFr3ZhZStUqv8/) and 6man (https://mailarchive.ietf.org/arch/msg/ipv6/iHvRL9SwSY-gMEpLuM0uhZdnytM/). No follow-up in these lists.
* The authors systematically sent a notification to SPRING/6MAN when new revisions were released (e.g., https://mailarchive.ietf.org/arch/msg/spring/E7E8SEKuP2gjklFxljZR6WwwvLU/), including when a call for adoption was initiated in OPSAWG and then past adoptions.
* Early versions were presented at OPSAWG and SPRING (IETF113) and 6man (IETF 114)

==

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://trac.ietf.org/trac/ops/wiki/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://trac.ietf.org/trac/iesg/wiki/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/